The future deployment of the RCS (Rich Communications Suite) service requires the use of IMS networks. IMS (IP-Multimedia Subsystem) technology was designed both for third generation mobile telephony networks, 3GPP, and for networks of other types, such as WiFi networks and other independently accessed service platforms, including broadband access through a landline.
IMS (IP-Multimedia Subsystem) was designed to allow operators (as stated, mainly mobile telephony operators, although they can also be of other types) to provide a wide range of multimedia services in real time, allowing the co-existence of these advanced packet technology-based multimedia services with traditional circuit switching-based services.
The IMS networks of mobile operators currently offer the possibility for users to set up multimedia sessions with content of any type such as voice, video, images, instant messaging, sending files between two terminals through a wire or wireless data link and an infinite number of additional services. These sessions originate from a user (user 1) of one operator (operator 1) through an IMS network and will end in user 2 who can belong to the same operator or to a different operator (operator 2).
These IMS networks are in an early phase of deployment in which there are no LTE (“Long Term Evolution”, fourth generation networks) radio access networks; in these LTE networks, the quality of service (QoS) would be assured for multimedia sessions. At present however, this is not the case for IMS networks.
In currently deployed IMS networks, there is certain control over the quality of service when accessing through the radio access carrier of the communications operator, but there is no reliable control over the quality of service as it exists in other networks, such as in circuit-switched networks, where the quality of service offered is assured.
This problem is aggravated because the IMS networks are independent of the method of access, i.e., in addition to the radio network of the mobile operator, any packet carrier such as a public WiFi network or any provider may access the IMS network. Many of these accesses are unrelated to the operator providing IMS services and therefore the operator does not control the quality offered and consequently cannot assure the QoS necessary for determined services. For this reason these new multimedia communications (of services such as RCS or other multimedia services over IMS networks) do not comprise the use of voice communications because it is a real-time service which does not allow latencies or excessive losses of packets to maintain a good voice quality, therefore the voice would need a certain quality of service assured (as is done by the carriers of the operator in the switched network carriers).
It can thus be stated that the RCS service presents the problem that in current IMS systems (until the LTE networks are completely deployed) the quality of service cannot be assured and in many cases, the same quality of service (“best possible performance”) will be offered to all users and, therefore, services requiring assured quality (such as voice services) which a priori could be offered over the IMS network, cannot appropriately be offered.
In services for exchanging data or video between terminals, the “best possible performance” of the radio access network is usually accepted by both the user and by the operators for this type of service even though this may represent a lower level of quality than is required and, therefore, it is possible for these services to use the IMS network without assured quality of service. However, this poses a question: “what happens if the user requests a service which does require a minimum quality that would not be assured by the IMS network?” Said service could not be carried out or it would be offered with poor quality. An example of this is voice communications, where echo and unintelligible or broken up voice scenarios could occur if the quality of service is not assured.
Hence, users of these services and other multimedia services over IMS networks need to be registered in the IMS network but further remain registered on the switched network to receive voice, which is a service that needs assured quality, in addition to SMS and MMS. This gives rise to a new scenario in which the same terminal/user is simultaneously registered in two networks (IMS and CS network), being able to receive communications from any of the two carriers. This situation has not happened until now.
Moreover, in this scenario, the currently deployed IMS network does not assure the operator that the user in an IMS Session will be provided with multimedia sessions with a different quality of service according to the type of user, offering better service (prioritizing) to special users (for example those who pay higher rates). In other words, it has the drawback that the IMS network in current systems will not allow the user to access multimedia services with a better quality of service even though he is willing to pay for it or has a greater need, which is a lost business opportunity for the operator.
Nor will present implementations allow, therefore, offering a different quality of service depending on other factors, such as the origin of the user, network load, time of day or any other factor that may be useful for the operator when differentiating the quality of service offered.
Therefore, it is necessary to solve these problems of systems used today and this is the purpose of the present invention.